The present invention relates to systems for purifying and dispensing drinking water in the home, and more particularly, to a system which provides a visual signal above the sink confirming an acceptable level of purity of water supplied by a below-the-sink or otherwise remote reverse osmosis purification apparatus each time the water is dispensed to the user from a third faucet mounted above the sink.
In many areas the water supplied to homes by water companies through underground pipes, wells or other sources contains high levels of dissolved solids, such as minerals, as well as agricultural nutrients, insecticides and other dangerous chemicals. These dissolved solids and chemicals can give the water an unpleasant taste. Because of the bad taste and the health hazards posed by such contaminants in the water many persons drink purified bottled water purchased at grocery stores or delivered by bottled water companies on trucks. Bottled water is relatively expensive and it is cumbersome to deliver and handle the bottles. Therefore, home water purification apparatuses have been developed and are now in widespread use. Typically such an apparatus is installed below the kitchen sink and is connected directly to the incoming sink cold water line. The purification apparatus removes a substantial amount of the dissolved solids, chemicals and other impurities before delivering the purified water through a third faucet secured to the kitchen sink next to the conventional hot and cold water taps. The percentage removal of dissolved solids, chemicals and other impurities by the purification apparatus indicates the initial and continuing relative efficiency of the apparatus.
A common household water purification apparatus is the reverse osmosis type in which water is forced through a semipermeable membrane. This membrane is contained in a removable module inside a pressure vessel. The purified water is temporarily stored in an accumulator connected to the third faucet. The efficiency of a reverse osmosis apparatus in removing dissolved solids from the incoming water begins to decline significantly once a given volume of water has been processed, for example, several hundreds of gallons. The removable module in the purification apparatus must then be replaced with a new one by a maintenance person or a skilled user to ensure that it once again delivers pure water having a concentration of dissolved solids which is below a safe maximum. In extreme cases the module may rupture or otherwise fail mechanically and will cease to function at all.
Reverse osmosis water purification apparatuses which are presently in widespread use are typically serviced when the user calls the rental or service dealer to complain that the water from the third faucet tastes bad or when the user feels that enough time has elapsed to warrant servicing. The dealer then instructs the user to fill a vial with a sample of water from the third faucet and mail or otherwise deliver the sample to the company for testing. If the test indicates that service is necessary, the service personnel is dispatched to the user's location to replace the module and check out the purification apparatus. By the time that the purification apparatus is serviced it is possible that the user will have consumed a significant amount of impure water. This is especially so if unsafe water was dispensed even before it began to taste bad or tests were made. If the test indicates that the water is still acceptably pure, then the company informs the user that servicing is not yet necessary. Either way the inefficiencies of such communication and testing result in inaccuracies, extra expense and lost time.
Regular scheduled maintenance on the purification apparatus is also not a desirable approach. A family may use the third faucet often enough so that membrane in the module degrades and unsafe water is consumed before the service personnel can correct the problem on a scheduled visit. Thus the water delivered by the purification apparatus may contain an unacceptably high level of impurities. However the level may not be high enough to be perceived by taste and the family may not know that they should have the purification apparatus serviced earlier than scheduled. On the other hand, a family may use the third faucet so infrequently that the water delivered by the purification apparatus may still be very pure when tested by the maintenance personnel on his or her regularly scheduled service call. If the service call was not yet necessary the result is wasted time and expense.
Without some sort of readily observed purity indicator a person dispensing water from the third faucet simply cannot be sure that they are consuming pure water at any given time. This may cause anxiety in many people, and in health conscious individuals in particular. Moreover, actual harmful effects on an individual's health can result from the consumption of impure water. For example, some regions have naturally occurring arsenic, high fluorides or asbestos fibers in the water supply which can be reduced to safe levels by a properly functioning purification apparatus.